聚合氯化铝对煤泥浮选的影响研究

Effect of Polymeric Aluminum Chloride on Coal Flotation

为探究不同浓度聚合氯化铝(PAC)对煤泥浮选的影响,将250~125μm的煤炭与-100μm的高岭石混合进行浮选速率试验,结果表明加入少量PAC能降低水回收率、脉石回收率和夹带指数,同时可燃体回收率少量增加;当PAC量达到50mg/L时,夹带指数增加的同时浮选速率与可燃体回收率也显著增加,三个浮选评价指标(EI、SER、SI)显示,当PAC浓度为20mg/L时,浮选效果达到最佳;采用不同浓度的聚合氯化铝对高岭石进行凝聚试验,用聚焦式光散射测量仪(FBRM)在线测量其粒度变化,结果表明,随着PAC浓度的升高,高岭石的粒度先增大后减小,在PAC浓度为20mg/L时达到最大;利用不同浓度的聚合氯化铝与煤炭作用之后测定不同接触时间下的气泡-颗粒粘附概率,从而探究聚合氯化铝对煤炭疏水性的影响,试验结果说明PAC降低了煤炭颗粒的疏水性,与浮选速率降低的结果一致,同时浮选结果显示疏水性的降低并没有对最终可燃体回收率产生负面影响。

To explore the effect of polyaluminum chloride( PAC) of different concentrations in coal flotation,flotation rate experiments were conducted with the mixture of coal( 250 ~ 125μm) and kaolinite(-100μm). The experimental results show that the addition of a little PAC can reduce water recovery,gangue recovery and entrainment index,meanwhile combustible recovery was promoted. When the concentration of PAC was 50 mg/L,the entrainment index,flotation speed and combustible recovery were all promoted The three flotation evaluation indexes( EI,SER,and SI) showed that the optimum flotation efficiency was obtained when the PAC concentration was 20 mg/L. PAC of different concentrations was used to agglomerate kaolinite,and the unweighted chord length distribution of kaolinite suspensions was measured by the Focused Beam Reflectance Measurement( FBRM). FBRM measurements showed that with the increase of PAC concentration,the chord length distributions of kaolinite increased first reaching the peak at 20 mg/L and then decreased. Bubble-particle attachment probability measurements were carried out with the coal which was interacted with PAC of different concentrations. The bubbleparticle attachment probability measurements showed that PAC reduced the hydrophobicity of coal particles,which matched well with the reduction of flotation rate. However the final combustible recovery is still promoted.